Cooling system for internalcombustion engines



COOLING SYSTEM FOR INTERNAL-coNsusTroN ENGINES Filed April 22, 195o Sept. 2, 1952 H. H. ALBlNsoN 4 Sheets-Sheet 1 (Ittorneg 311m ntor Gttomeg NSMMQ( 4 Sheets-Sheet 2 H H ALBINSON COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Sept. 2, 1952 Filed April 22, 1950 Sept. 2, 1952 H. H. ALBlNsoN COOLING SYSTEM EOE INTERNAL-COMBUSTION ENGINES Filed April 22, 195o 4 Sheets-Sheet 5 H. H. ALBINSON COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Sept. 21952 4' Sheets-Sheet 4 i Filed April 22, 1950 MLN?. /f l/` W f l? W w MT? mT W l W f Patented Sept. 2, 1952 COULING SYSTEM FOR INTERNAL- COMBUSTION ENGINES Harold I-I. Albinson, Detroit, Mich., assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application April 22, 1950, Serial No. 157,585

(Cl. 12S-41.28)

44 Claims. 1

This invention relates to internal combustion engines and has particular relation to cooling systems for two-stroke cycle compression ignition enginesy for use on trucks, busses, small boats, and other light weight load carrying vehicles, andon other devices or apparatus, where the space occupied by the engine and the weight and'cost of thevengine are important factors in the design of the engine.

An object of the invention is to provide a short, compact, inexpensive and light weight engine adapted to operate on inexpensive fuel and service and to employ such fuel in a two-stroke compression ignition cycle where relatively high temperatures will be developed in the operating parts of the engine, and, where an effective and eicient cooling system is required to prevent the cost,'weight, and size of the engine from becoming excessive.

"Another object of the invention is to provide an engine cooling system in which both pressure circulation and thermo-syphon circulation of cooling iluid are employed. A

= Another object of the invention is to provide an engine block having a cooling liquid circulating Ysystem formed therein, and in which circulating system the cooling liquid required to fill the cooling passages within the block and in the engine radiator, will be reduced to a minimum, and wherein such cooling liquid will be circulated at relatively high velocities over the parts of the engine requiring the greatest amount of cooling and' at relatively lower velocities over parts that require less cooling.

`Another object of the invention is to limit the application of cooling liquid to the hottest parts of the engine and to employ other cooling means for other parts of the engine where such liquid cooling may not be required.

Another object of the invention is to provide an engine cooling system in which the exhaust ports and passages for the engine will be cooled by all of the cooling liquid supplied to the engine and wherein the cooling liquid employed in cooling-such ports and passages will then iiow past the head end of the cylinders of the engine and then either into the engine head of the engine and to the radiator of the engine, or to other and cooler parts of said engine for cooling such parts and for the dissipation of excess heat therefrom.

Another objectyof the invention is to provide a cooling system` for compression ignition engines which will require a quantity of water that will be smaller thany ,the quantity of Water that would be required to cool a conventional spark ignition engine of the same horsepower.

Heretofore it has been the practice to construct compression ignition engines in such a way as to weigh more pounds per horsepower, to occupy more space per horsepower, and to require'more cooling liquid per horsepower than other engines of conventional design. The compression ratio is high in such 'engines and it has heretofore been considered necessary to employ an excessive number of pounds of iron to construct aV block for such an engine, and, since the ignition temperature is also high, it'was considered necessary simply to make the water circulating passages-in such a block large enough so that in any event the engine would be cooled. y f According vto this invention,` it -is proposed to employ a relatively small light weight engine block inrwhich the cylinders are placed about as close together and to the side walls of the block as they might be placed in any conventional spark ignition engine and to eiliciently cool the parts of the engine that require excessive cooling by providing rapid circulation of cooling liquid over such parts and then to cool other parts of the engine not requiring excessive cooling means other than the directcirculation of cooling liquid thereover. For a better understanding of the invention, reference may be had to the accompanying drawing forming a part of this speciiication, in which:` Figure 1 is a side elevational view of an engine embracing the principles of this invention and having certain par-ts thereof broken away to show the interior of the engine in vertical sectional vlew. f Figure 2 is a cross-sectional view of the engine taken substantially in the plane of line 2-2 ori Figure 4. l

Figure 3 is another cross-sectional view through the engine shown by Figure 1. Figure 3 is taken substantially in the plane of line 3-3 on Figure 4.

Figure 4 is a fragmentary transverse sectional view through the engine shown by Figure 1. lFig-- ure 4 is taken substantially in the plane of line 4 4 on Figure 2. A'

Figure 5 is a fragmentary vertical sectional view of the engine taken substantially in the plane of lines 5-5 on Figures 2 and 4. v y* y Referring particularly to Figure 1, the invention comprises an engine I0 having cylinders I I, I2, I3, and I4, and containing pistons I6, I 'I,. I8, and I9, for driving crankshaft 2l. through connecting rods 22, 23, 24, and 26. The crankshaft 2l is adapted to drive a truck, bus, boat, or other vehicle or apparatus with which the engine may be employed, through a suitable and conventional clutch and transmission mechanism indicated at 21 and secured to the block 28 of engine I by bolts indicated at 29.

The front endgof i the crankshaft `:.2`I terminates in a flywheelandidrivepulley 3| which drives an engine fan 32 through a belt 33 and a pulley 34. The fan 32 and the pulley 34 are supported by 'af stub shaft 36 which projects from a housingof a pump 31, which is supported by the-.frontend of the block 28 and is secured removably thereto as by cap screws indicated* at3|3zv The front end of the crankshaft' 2I 'also projects through a gear housing indicated at 39 which is also secured to the front end'. of thef-blocklby screws or other suitable means, not shown. The gear housing 39 contains suitable -drivegear mechanism for driving a camshaft indicated in Figuref 4 at.'4|:

The housing-.139' also may-containandzthadrive gearl mechanism. therein. may: drive;- a. suitable pump; notrshown; for: circulating: lubricating oil tl-irouglioutl the lubricating system ofi the?, engine:

The-water pump 31.' is4 proyidediWitlranutlet connection 42 'tonwhichthe inlet. connection. 43 off lubricating` oil.` cooling. jacket 44 is. connected by'fa; hosef46i Water. from; thef lower: partof the liquidcooling radiator; noti shown',v is. supplied` byl the-pump 3.1" to the.l water: jacket 44l and; at thepressure provided. bytheL pump referred to;

Tlief jacket?. surrounds ai.. multiple: tubular pl'ater-l lubricating.` oil cooler:v 48 andi. is secured .to plate- 4912 supporting: theicooler: by; an .outwardly projecting flange 41. Thezplate-49fis secured-by bolts-012 other suitahlemeans; notzshown',4 to.. one side-of the-block: 48 alongthe-upperyedgeof1 the block and-V with one endl thereof. adjacent: the front of; the block and the opposite.- end.v projectingtowardithenrear; end; thereof. Agasket.- I is employed'between'the plate-.4&- and. theblock 2.8 fonpreventing'anyleakageof uid. therebetween.- The-block: 28 fis'.- prov-idedgwith.amore-opening in.- dicated'at-BZI- andaformedin one-sidexthereof, the core. opening: 52'sheing-1 covered. by, the.: plate 49 when-.theapiatei-is-secmed tothe block. 2.8 upon the gasket 5I.

Gpposit'e the inlet143 f and beyondthe .cooler-48 thjacketzisiprovided with-.a dischargechambenilndi'catedi. at; 53.. which communicates- Withregisteringz openings; 54- and 56- formed. in. the plate;49:.and;the block 28?' respectively.

Gooling; supplied: by, thez pump. 31- is? di.- rectedzby thejacketi44-across;the=surfacefof the lubricant cooler 48, into the discharge passage- Bzairfthe .end ofithe ,cooler 48-, ,and, into thefblock 28. throughlregistering passages:V 541 and. 56.

Lubricating oil to be cooled is supplied tothe conlerf48fthrough. anpassagerA which is formed. in thee-block 28: and which; communicates at., the lowerfendthereof withtha lubricating oil pump of the engine which was previously referredto containedzw-ithin the. housing. 39. The lubricating. oiltso .supplied to the-.cooler 481 isdischarged?.ffrorrr the-'opposite endofv the cooler through an opening 58 which is also-formedin the block-:281 and: which communicates.- at#V the.A lower extremity-thereof y withan. oil .cleaningi and cir-cue lating deviceassociatedrwithf` a-f camshaft 4-I whichrismounted. inothe lower. partof the block28 andadjacent .one side of the. block ZS.

-Itfwill.b'e...app arent.that the lubricating oil cooler 48 willlbecooled by the coldest cooling liqudlwhich.the.liquidjcoolingsystemofthe engine provides, this being the cooling liquid delivered directly from the radiator of the engine and by the pump 31.

The engine block 28 comprises a pair of oppositely disposed side Walls 59 and 6I, a pair of oppositely disposed front and rear end walls 62 and 63 respectively, and a top wall indicated at el.

Cylinder shells- 66, 61; 68 and 69 are-'disposed Within the block 28 in spaced relation to one another and to the side walls 59 and 6I and to theendwalls 62 and 63. The shells 66, 61, 68, and 69l'are formed integrally within the block 28, and aligned with respect to one another and are disposedr in' parallel relation to the side walls 59 and 6-'I Within the shells' 66, 61, 68, and 69 are cylindensleeves- 1|; 12; 13, and 14, the sleeves and shells respectively comprising the cylinders II,

I2; I3, andl4.

Camshaft 4| (see Figures l and 4) is mounted irrbearings 16: which extendfronr the-frontLtozthe rear; of thefblock 28: and, which. are` formed inetegrally with; the; side'- wall;V 591i and: the; lower: ex;- tremitieszof: the'v cylinder.L shells': indicated. at: 661, 6.1-, 68', vand;` 69. Locatedabove theibearings-.16 is. aypartition-wall 11 which-.alsofextends-between the side; wall;59 vandstheglower;extremities of the cylinder: shells; |56; 61,68; and 69. The partition 11 is connected between the-icylinderfshell'szSB, .611'

, 68,. and 8.9 tothe upwardiedge, or extremityof a botliom1=wa11l18 which :slopesi upwardly@ withinlthe block 128i towardsthetcylindershells 66;. 61; 68, `and 69' and from the.V lowerxedgefof; the;- sidef-wallfj: Thegpartitiorr 11` andzfthe.- inclinada-.or sloping-" jwall 18', provides a; bottom; wall'. for the space: Within the, block-i281I and .surroundingrtheacylinder shells 66; 6.1, 68, and .Stand aniupper. waihfor the. crankcaseo1 the enginand: indicated'.- 'at-t19- in Figures 1 and 4.

Disposed betweenxthe side wall-SafandztheLcylindershells 66, 6:1;.68,.and169fareit11bula1rpassage members. 8 I., 8-2, ,83, and .84I whichare seeured'at opposite ends in openingsfformed: in the-.torn wail- 64 andzthe partitiozrwalljl ofzthelbloclQZR.: The passagermembersv 81|-, 82; 83?,.andl84: eachihayer reducedlower endsiindicatedfat zandfoutwardly flanged` upper.: ends;Y indicated .at 8.1 tozpermitthe passagemembers vto.-bezremovably'insertedsin the block. 28 from. outsdef. thm upper- 64 of the block. WithinthepassageAA members 8|, 82,831; and 84 are: push rods; 88,- 9|, and;92zrespec tively, eachpush.rodbeingprovfdedwith a'. cam' follower y93 which-is` secured betweenzthebifuricated ends of a follower memberr94; Onefofithe' followerz members- 9IIV isi secured `tzr the t lower exlzremityyofiv each. of'. thefpushrods 8.8;- 89'-, 9|; and

The followers; 93:V are: adapted tovbe operated by the camshaft 4|.foi1 timing. the injectioniof.`A fuel tothe cylinders II I2; I 3, andI4'.

The upper ends. ofthe. pushrods 88, 89', 9.1, an'd 82-Y operate -conventionalarcuately moving-rocker` arms anda, rockenshaft; noizshown', but con;- tained, within a.; cover 916 thaty may beremova'bly secured .to 1 the,v uppersurface of an: enginehead 91, which. inturn removably secured to" the block. 28 by' capscrewaindicatedi at 98* in Fig-"- uref-4. Therocker: shafts referredJtozare-.adapted to time; the` operationofi ai. pluralityv of: fuel in jection valves-.99,- one. of.- Whichjsfprovidedifon each of the cylinders indicated at |I, I2, I3,.and: I 4. The .injection valves.- 99; are -secured-in-openings formed transversely across thehead 91t-w-hich. 1n turn. open intocompression spaces-'IUI pro-` vided in the. lower surface. of. thehead.. 91. and opposite each of'the cylinders II. I2, I3, and I4.

Disposed in Vparallel relation to-the upwardly sloping wall 18 is another upwardly sloping wall which is indicated by the numeral |02. The wall |02 is disposed and spaced above the lwall 18 and is formed integrally with the block 28 along the lower portion of the side wall 6I. The walls 18 and |02 also are formed integrally with the lower parts of the cylinder shells 06, 61, 68, and 69 and project between suchl shells and there terminate in sections of an upper wall indicated at |03.

Formedbetween the lower parts of the inclined walls 18 andv |02, the side wall 6I and the lower parts of the cylinder shells 66, 61, 68, and 69 is a charging and scavenging fluid inlet manifold indicated generally at |04 and supplied with such fluid by a blower, not shown. The spaces between the cylinder shells 66, 61, 68, and 69 and the upper parts of the walls 18 and |02 and be-V low` the wall |03 provide branch passages |06 for the manifold |04, such branch passages being adapted to supply such scavenging and charging uidto the cylinders II, I2, I3, and I4, through inlet ports |01 which' are formed Ain the cylinder sleeves 1|, 1.2, 13, and 14. One of the passages I 06 extends between each of the cylinders I2, I3, and I4 and one extends between the end wall 62 and the cylinder I I and another between the end wall 03 and the cylinder I4.

Formed integrally with the block 28 and projecting across the block from the cylinder shells 66, 61, 08, and 69 t0 the side wall 6| is a plurality ofgroups of spaced exhaust passages indicated at |01, |08, |09, and III, there being one group of passages for each of the cylinders respectively. Each of the groups of the exhaust passages comprises three exhaust passages which are disposed in spaced relation to one another and which extend between the exterior of the block 28 and a like number of exhaust ports II2 which are formed in each of the cylinder sleeves 1I, 12, 13, and 14 in opposed relation to the passages of each group of passages indicated by the numerals |01, |08, |09, and |II. When the exhaust ports ||2 are uncovered by pistons I6, I1,

I8, and I9, the exhaust passages referred to provide communication between the interior of the cylinders II, I2, I3, and I4 and the exterior of theblock 28.

The passages |01, |08, |09, and III are aligned with respect to one another across the block 28, are relatively horizontally `disposed within the block 28, and are spaced within the block above the inlet manifold |04, to provide a cooling liquid distribution passage, manifold or chamber indicated generally at II3.

Formed in the block 28 between the exhaust passages in the groups indicated at |01, |08, |09, and III are exhaust cooling passages indicated at |I4, IIB, IIT, and |I8. These passages each comprise a pair of passages extending between the exhaust passages of each group of passages indicated at |01, |08, |09, and III. The lower extremities of the passages ||4, IIE, |I1, and |I8 each communicates with the liquid distribution chamber indicated at ||3, while the upper extremities of said passages in turn communicate with a cooling liquid receiving passage II9 which is formed in the block 28 between the upper wall 04 and the groups of exhaust passages indicated at |01, |08, |09, and III. The groups of exhaust passages indicated at |01, |08, |09, and III also are spaced from one another to provide a further series of passages indicated at |2I, |22, |23, |24, and |26 and the lower ends of which passages also communicate with the cooling liquid distribution manifold indicated at II3.- The 6 upper ends of the passages |2I, |22, |24, and |26 likewise communicate with the liquid receiving chamber or passage I|9 which is formed above the group of exhaust ports indicated at |01, |08, |09, and III.

However, the passage |23 which is formed between the groups of exhaust passages indicated at |08 and |09 is provided `with upwardly extending wall sections indicated at I 21 which terminate in integral relation to the upper wall of the block 64. The passage |23 therefore divides the liquid receiving passage ||9 into a pair of receiving passage sections indicated at |28 and |29. The wall sections |21 also extend from the side wall 6| to the cylinders I2 and I3 and therefore cut off all communication between the passage sections |28 and |29 and the space between the cylinders I2 and I3 and to the opposite side of the block. The space between the walls |21 and the space between the cylinders I2 and I3 does, however, communicate with the cooling liquid distribution manifold space between the adjacent exhaust passages in the groups |08 and |09, thus providing a fluid supply passage for the distribution manifold ||3 which lleads Afrom between the cylinders I2 and I3 and through the passage |23.

The space between side wall 59 and the opposite side of the cylinders II, I2, I3, and I4, provides a plurality of cylinder cooling cavities indicated at |3I, I 32, and |33. These cavities extend around the tubular passage members 8|, 82, 83, and 84 and hence cool these members throughout the entire length thereof. The cavir ties |3I, |32, and |33 also extend from the top wall 64 of the block 28 downwardly on one side of and between the cylinders II, I2, I3, and I4 to the partition wall 11, and around the curved upper ends of the divided parts of the inclined partition wall 18 to the spaces between the cylinders and above the upper wall |03.

The cavities |3I, |32, and |33 are separated from one another by web walls |34 and |36, these walls being formed in the block 28 to project outwardly from the side wall 59 and from the cylinders i2 and i3 respectively. These outwardly projecting web walls are adapted to engage and to fit throughout the length thereof within the block 28, the oppositely disposed sides of the passage members 82 and 83.

The cooling cavity |32 therefore is limited in longitudinal extent by the passage members 82 and 33 and the web walls |34 and |36. Cooling cavity |3| likewise is limited in longitudinal extent by the end wall |52 and by the passage member 82 and the web walls |34 and |36 which the passage member engages. Cavity |33 likewise is limited in longitudinal extent by the end wall 63 and the passage member 83 and the web walls |34 and 36 with which the passage member 83 is likewise engaged.

The cavity |32 therefore extends from the side wall 50 and from between the passage members 82 and 83, upwardly around theA curved end of one of the parts of the lower wall 10 which extends between the cylinders |2 and I3, over the top wail |03, between cylinders I2 and I3, and' into the space between the cylinders I2 and- I3 and providing the extension. passage I 31.` Beyond extension passage |31 the cavity |32 is in open communication with the upper end and the side portion of passage |23 which at its lower end communicates with the central portion of distribution passage I|3.

Cavity |33 likewise extends from tubular member 83 to end wall 63 and from side wall '59 up- I3 through theV waxdlyxandfiaroundtheoun!edzuppenensisfof-two: pantsotftheinolined Wall 18;- ansiroLthetop-Wa1li loa-:these-beingz the.; parts .thatz-fproieot between. the;- cylinders I 3-andA I4;v to.; the.l spacesbetween the cylinders I3 and |4 and betweenthe cylinder |-4:-:and:.the endzwall 63?; The; cayity l 33.-.the1ef91e has ltwo-.extensions abovethewall; |83, Whichare indioatedgatd 38s andv |39g.` anti;-V Which lproject between. the-cylinders |3-and'- I4 andA beyond` the cylinders I3-and` I4 into.-communicatiomwith the; sectioneonbranch |29 of- ,the-liquid receiving pas.- sage |19..y

Cavity |3.| likewise extendsfrom tubularvmemben 82:;to the end; wall 62 and from side wal1'59 upwardly around-the1 curvedends of the parts. off-the-wallI 18zandA above the. Wall |83 and into estensioniI passages |421 and |4.| which extendrespectivelygbetween theend Wall 62 and the-cylinder. |1| 1 andbetween the cylindersl ||4 and` |2- andi above the-wally |03. extends through extension passages |4'|- and |42` and into-communication with Vthe branch |28 fof thereceving-.passage I I9;

It.will"ibe; apparent that.l cooling uidjwhich is introduced-into cavity. |32 through the registeringr-openings.54;iandf56f'andfrom the jacket 44 will flow across theeblock 28: through extension passage-|31", into the upper extremity ofI passage |23? between the walls-V |21;l and downwardlyl through the passageV |23 and into the central por-tions@tithe-distribution manifold ||3. From such- :centralportion of'the cooling liquidy distributionmanifold ||3`V theliquid will ilow toward the-fronts and rear ends of the block 28 between the upwardly sloping wall' |82 and lower walls of'fthe= exhaustpassages in theA groups |81, |88, |89; and I. The liquid thereafter may flow upwardly through the exhaust cooling passages indicatedati I4,` H16; II1', ||8, |2'I, |22", |24, and |26. Since the upper endsof passages ||4and H6 communicate .with the branchl E28-of liquid receiving passage ||9, and since the upper ends and side portions of the passages I2 I' and |22 also communicate-with thebranch |28 of the liquid receiving passage H9, the liquid which ows upwardly-through all of the foregoing passages will be--freeto flow through the extension passages |4|- and |42 and into the cylinder cooling cavity |.3|.-`

The exhaust coolingpassages ||1 and ||8 and the passages |24 and |26 also similarly communicatewith branch receiving passage |29, with the extension lpassages |38 and |39, and in turn with cylinder cooling cavity |33.

Directly above the extension passagesMI, |42, |31; |38, and |39, are outlet passages indicated at |43; and |44, these passages being formed irland adaptedtoextend through the upper wall 64 of block 28. The passages |43 and |44 are arranged in pairs, there being one pair of these passages for each of the extension passages |4I, |42, |31, |38; and |39.:- The passages |43 and |44 of each pair ofpassages are arranged on opposite sides of` the center line through the axes of the cylinders=|'|, I2, I3, and |4 and inside of lines that might be drawn tangent to the cylinders at oppositeisides of the cylinders.

The-passages |43r and |44 which are formed inthe. top wall 64 of the block 28, are aligned with similar passages formed in lower wall |46 offthe-head 91. The openings in the lower wall |46 of: the head 91 and referred to as being aligned with openings |43.and 44 alsol are indicated by numerals |43 andjl44.

- Thecheadllis fprmedin such a, way as topro-- Cavity |3| therefore-` ao'lapted-v tote supplied to; the; iilteltiol:4 oi: the. cover--Sfby taking .-offfthemier;oapnclioatediat:

|51 whichcovers the; ,inlet end; oi 1a.: ansesista ting |52J the latterteinaseoured tothe-.coverfz byl serews,| 53'. Alubrieantfso intnoduoedfto the one end to. v`the other-off therheod: 91 and; there after. will; flow -to; the orenkoasef of. the engine,vv through; the-:passage-membersrindioated at s l. 8 2.. 83;'a11d184:

The lower-end Aof 'the cranlcase -1 9' is covered 'bythe,l usual crankcase-pan or--cover-indicated by the. numeral llill-thusretaining-withinthe engine an oil supplyfrom which the engine is lubricated'.-

The .crankshaft-2 I -Whichis-adaptedto-operate within -thegcrankcase 19A is supportedbybearingswhich are;V indicated-generally at 54;-and'- whichare formed inblock 28;v between; each ofthecylinders |2, |,3-,-and,|4.y The bearings. |54, are-securedjto the;v lower parts Qf'- eachof the. cylinder shells-,66, 61,- 6 8-, and" 69 -by-transverse walls indicated at.; |56. 'Iheopposite ends ofeach-ofthebearings are extended to provide rows of l integral columns |51 and 58` which, projectupwardly; Withinthe block and 'in-parallel relationto theaxeskofthegcylinders- |2-, I3 and I41 andbetween eachV of the-fcylindersandthe sidewalls 59and li I; The-top o r upperends -ovf-the columns |51andjl58 areseured 4integrally` to the top; Wall,l 64 of the-- block 2li-and; are likewise secured inf. tegrally to: the.' walls of4 the vet-rions` passages formed --insideA the block 28` andA whichwalls all4 are securedY directly or indirectly to the sidewalls 59 and 6| and to the cylinder shellsl 66,; 6 1,A 68,; and (i9.l

'The Water? 01': 01311911" Cooling liquid sllppled by' the pump-3T Will flow-into.` the-oil cooler jacket 4,4- through the coupling 46. The oilgcooler-jacket- 44:15; made-toolosely -ttheoil cooler 41 conf. tainedwithin thejacket so lthat the velocity offlow of liquid over the, cooler 48 will be-aboutas-highasfthe velocity of flow of liquid fromthe openingsv 54-and 56 leading tothe cavity |32.-and

the extension passage |31 leading -from the cavity |32 that thisgrelativelyhigh velocity jet ofVr cool. ing liquid will tend `to travel-directly across the cavity 3 2 and through the extension passage |31 with '1ittle interference, from the remainingquanti-tyoi liquid required to il'll the cavity. |32. Fromextension passage-,|31 asimilarjet-` likestreamof,.wate r will flow downwardly through the` passage |23 and into the central portion Qfrtheliquid distribution manifold ||3'. Inthe,

fnanifold- H3 such stream'of water will spread out in bothdirections to the front and rear ends of the block 28 and will ll the passage or distribution manifold H3.

It will also be apparent from observing the cross-sectional area of the exhaust cooling passages indicated at H4, ||6,VI|1, and H8 and of the passages |2I, |22, |24, and |26 that the upwardly directed flow of iiuid through the passages referred to and from the distribution manifold H3, and into the branches |28 and |29 of the receiving passage I9, also 4will be at a relatively great velocity.

It will likewise be apparent from observing the cross-sections of the extension passages |4|, |42, and |38 and |39 that the velocity of the flow of the cooling liquid received from branches |28 and |29 of the receiving passage H9, will likewise be relatively great.

However, the opposite ends of the extension passages |4| and |42 communicate with cylinder cooling cavity |3| from which there is no liquid outlet, and, extension passages |38 and |39 likewise communicate with cylinder cooling cavity |33 from which there is no outlet.

It will therefore be apparent that the relatively high velocity streams of liquid in the extension passages |4|, |42', |31, |38, and |39 will tend to vflow upwardly and into the head 91 through the pairs of outlet passages |43 and |44v and oneof which pairs of outlet passages is located opposite each of the extension passages ll, |42, |31, |38, and |39.

The liquid, therefore, will flow into the head 91 through vpassages |43 and |44 in a plurality of relatively high velocity streams.

The liquid capacity of the cavity |41 extending fromone to the other of the head 91 is intended to beV relatively small, and in such cavity these high velocity streams will tend to be deflected by `upper wall of head91, and will be compelled to flow rapidly through the head91 and toward the outlet |48. .From'theoutlet |48 the cooling liquid will be delivered tothe radiator of the engine throughfthe coupling' |49.

"From the foregoingand from observation of all of the figures ofthe drawing, it will be apparent that the cooling` liquid in both the head and the block of the engine is forcibly directed at relatively high'velocities only over the engine parts and surfaces which tend to operate at relatively high temepratures. The rest of the parts of thecylinders andparticularly the lower parts of the cylinders are cooled by what might be called relatively 'stagnant bodies of cooling liquid. By'this is meant cooling liquid that is not directly in the path ofthe high velocity streams of coolingv liquid that are forced through the various passages of the engine block or that are caused to flow in limited areas throughout the engine block by pressure of the-liquid and by the inertia ofthe particles of liquid in the liquid streams referred to.

For'example, there will be little circulation of cooling -uidi in the various cylinder cooling cavities indicated by numerals |3|, |32, and |33, except for the stream of liquid that is impelled into and through the cavity |32 by the registering inlet openings 54 and 56. Except for this circulation and'except for the forced circulation of cooling fluid in all of the extension passages |4|, |42, |31, and |33 and |39, there will be little forced or pump impelled circulation of cooling fluid anywhere withinthe cavities |3|, |32, and |33. Such circulation as mayl occur is these cavities will be caused by differences in tempera- "l0 .ture of the liquid which will differently aiect the liquid in different parts of the cavities |3|, |32, and |33.

Hence, practically all of the circulation of cooling liquid that occurs within the cavities |3|, |32, and |33 will be thermo-syphon circulation vof the cooling liquid. However, this circulation will occur to the greatest extent near the head end surfaces of thecylinder shells 66, 61, 68, and-69. Even such circulation will not occur to any great extent until the temperature of the water near the upper ends of the cylinder shells has increased to such an extent that the heated liquid will be able to overcome the velocity of the liquid in the extension passages |4|, |42, |38, and |39 and tending to cause circulation of the liquid in the opposite direction. When the temperature of such liquid is high enough to overcome the tendency referred to, then such heated liquid either will iiow out of the vicinityV of the top'of the shells 66, 31, BS, and 69 and into the head 91 through the' openings |43 and |44, or will flow across the top wall 64 and downwardly along the side wall 59 where the heat will be transferred to the atmosphere through side walls 59. The remainder of the liquid in the cavities |3|, |32, and |33 will tend to stratify at different levels and at different temperatures, and will tend to allow the tops of the cylinders to become relatively hot and the parts of the cylinders therebelow to` be progressively cooler. This condition of differences inthe temperatures of the tops and the bottoms of the cylinders H, |2, I3, and |4,is approximatelythe same as that which will ,aifect the opposite sides of the cylinders and where the exhaust passage portions of the cylinders will remain relatively hot while the lower parts of the cylinders affected by the distribution chamber H3 and the inlet manifold |04 will be progressively cooler.

It will be apparent, therefore, that the entire engine will be affected by two entirely .different kinds of cooling; namely, by forced circulation of cooling fluid, and thermo-syphon circulation of cooling uid.

By comparing the sizes of the various passages and cavities in the block 28, it will at once be apparent that the greater volume of cooling fluid in the block will be affected by thermo-syphon circulation and that the smaller volume will be affected by forced circulation.

' For example, the cooling exhaust passages in the block, the upper extremities -of the cylinder sleeves formed in the block, and the lower wall of the cylinder head 91 all will be affected by low volume, high velocity, pump impelled circulation of cooling iiuid, whereas the larger volume of cooling fluid contained within the cavities ,|3|, |32, and |33 will be almost entirely affected by thermo-syphon circulation of cooling` fluid.

`Under such conditions, it will be apparent that only a relatively small quantity of cooling iiuid referred to will flow into the block through the inlet passages 54 and 56 and from the block and the head through outlet passage |48. The temperature of such small quantity of liquid, however, will be relatively high, inasmuch as this'circulating liquid comes in contact only withtthe very hottest parts of the cylinder head and block. Consequently the liquid impelledvfrorn the outlet |48 might be said to consist of a relatively small quantity of cooling liquid having arelatively high temperature. It-is therefore possible'V to employ arelatively small radiator for cooling the engine, because the amount of heat which may be dissipated by any Vradiator under any given set 11 ofexternal conditions, `will depend upon-the'temperature of vthe cooling `liquid circulated throughout the interior thereof and the velccity'of such liquid.

iThe cooling system -for the engine therefore makes'itpossible to construct an engine block With-a relatively small capacity for containing coolingliquid within the liquid circulating Apassages thereof, and makes it possible to providefa relatively small and inexpensive radiator for dissipating the heat rejected by the engine. Also the pump and water connections for the'engine inaybe correspondingly small and inexpensive. Thesmall quantityvof Water used also is an advantage from the standpoint that in cold weather onlya Arelatively small quantity of anti-freeze solution will berequired in order to maintain the cooling `liquid in such vcondition that it will-not freeze when the engine is not running and vafter itv has been' allowed to cool off.

In theclaims:

' `1. Ar method of cooling the cylinders of an internal combustion engine which comprises, providing""a"pair 'of liquid circulating cavities on opposite'sides of a cylinder of an engine, providing extension'passages between said cavities at the upper'extremities of said cavities and surrounding the head endof said cylinder, and provlding forced'circulation of cooling liquid in- Wardlyatthe bottom'of one of said cavities and outwardly of said cavity from said extension passages.

2. A'Jmethod of cooling the cylinders of an internalcombustion engine 'which comprises, providing a pair of liquid circulating cavities on oppositesides of a cylinderof an engine, providing forced circulation of cooling liquid inwardly at the'bottom of one of said cavities and outwardly of said cavityfrom the upper extremity of said cavity, and providing thermo-syphon circulation and cooling of cooling fluid within the other of said cavities.

3. A. method of cooling the cylinders of an internal combustion engine which comprises,ipro viding a pair of liquid circulating cavities on oppositesides of a cylinder of an engine, providing extension passages between said cavities at the upperextremities of said cavities and surrounding the head end of said cylinder, providing forced circulation of cooling'liquid inwardly at the bottomof oneof said cavities and outwardly of said cavity from said extension passages, and providingthermo-syphon circulation of cooling fluid within :the other of said cavities.

4. A method vof cooling the cylinders of an internal combustion engine which comprises, providing a pair of liquid circulating cavities on' opposite sides of acylinder of an engine, providing extension passagesbetween said cavities at the Vupper extremities of said cavities and surrounding-the head end of said cylinders, and providing forced Vcirculation of cooling liquid to and from one of said cavities and thermo-syphon circulation of cooling liiuid within the other of said cavities.

`5. vA inethod of rcooling the cylinders of an internal ycombustion engine which comprises, providing apair of liquid circulating cavities on opposite sides and surrounding the head end of 'a cylinder of an engine, and providing forced circulationzof cooling-liquid to and from one of s-aid cavities and providing thermo-syphon circulation of cooling fluid within the other'of said cavities.

A6. Amethod-of cooling the cylinders of an internal combustion engine which comprises," providing apair of verticallydisposed coolinglcavities on ropposite sides of 'a row of said cylinders, connecting said vcavitiesatthe tops offsaid'rcavities and between and aroundS--the 'headends -of each of said cylinders, pumping coolin'g"liquid into the lower part of said cavitylat'one'sidefof said cylinders, v and distributing said liquid throughout the length vofsaid cavity.'condu'cting said -cooling liquid upwardly in "said fcavity through va plurality 'of-l parallel fpassages extending'from one end toanother of said cavityfexhausting saidcooling liquid from`1the'uppen part of said cavity, dissipating heat from said'fcooling liquidV in a heat exchanger positioned 'remotely -with respect to said cylinders, `returning ysaid liquid-to said cavity by againpumping said' liquid into'said lower part Iof saidv cavity,` andv dissipating heat from the other of said'cooling cavitiesfby thermo-syphon circulationof cooling 'fluid'within said cavity.

'7. A method of coolingthe'cylinders of an' internalcombustion engine which comprisesf-providing a pair of vertically disposedcooling-cavities on opposite sides of Aa row'o'f said cyliners, pumping cooling-liquid into the lower part of one of said cavities and distributing 4said liquid throughout the length of said cavity, conducting said cooling liquid upwardly in said cavity through a plurality of parallel passages extending from-one end to vanother of said'cavity,e'x hausting said cooling liquidfrom the upperpart of said cavity, 'dissipatin'g h'eatfromv said cooling liquid in a heat exchanger positioned remotely with respect 'to said cylinders, "returning said liquid to said cavity by again pumping said liquid into the lower part of said cavity, 'and dissipatingheat from theotherof'said'cooling cavities by thermo-syphon circulation of 'cooling iiuid Within said cavity.

8. A method of cooling'thecylinders of' an'internal combustion engine' which'compris'es, providing a pair of vertically disposed cooling'cavities on opposite sides of a row of' said cylinders, pumping cooling liquid into' thelbottomof'onef said cavities and distributing said "liquid throughout the' length of said cavity, 'conducting said cooling'liquid upwardly in said Acavity throughout a plurality of parallel exhaust cooling passages extending from one end to another of said cylinders and said cavity, .exhausting said cooling liquid from the upper parts of saidcavity, dissipatinig heat from said cooling liquid 1in a heat exchanger positioned remotely with respect to said cylinders, returningsaid liquid .to Vsaid cavity by again pumping said liquidinto the'bottom of said cavity, and dissipating heat lfrom the other of said cooling cavities -byfthermosyphon circulation of cooling iiuid Within-said cavity.

9. A .method of cooling `the cylinders `ofln ternal combustion engines comprising, pumping cooling liquid at relatively high velocities upwardly-and over the exhaust'passagesdeading from said-cylindersand around-a portion of y.the heads of said cylinders and awayvfromesaid :cyliners for dissipating the heatabsorbed by said cooling liquid in a heat exchange Adeviceloc-ated remotely from said cylinders, and cooling -the remainingv parts of vsaid cylinders bythermo-syphon circulation of cooling liquid in a heat :exchange device locatedadjacent said cylinders.

`10. A method of `coolingithe cylinders offinternal combustion' engines f' comprising, pumping cooling Yliquid at relatively high velocities -up Wardly 'and "over 'the exhaust passages "of sa-ld cylinders andaway from said cylinders for dissipating the heat absorbed by said cooling liquid in a heat exchange device located remotely from said cylinders, and cooling other parts of said cylinders bythermo-syphon circulation o-f cooling liquid in` a heat exchange-device located adjacent'said cylinders.

11, An internal kcombustion engine comprising an engine block having a row of engine cylinders formed in said block, said block also being formed to provide a plurality of cooling cavities for said cylinders, said cavities being located on different sides of said cylinders, means for pumping cooling liquid to and from one of said cavities and for dissipating heat from said .cooling liquid in a heat exchanger -located remotely from said cylinders, and means for dissipating heat from the other of said cavities by thermo-syphon circulationofV liquid in said cavity.

12. An internal combustion engine comprising an engine block having a cylinder formed in said block, said block also being formedto provide a plurality of cooling cavities Vfor said cylinder, means for pumping cooling liquid to and from one of said-cavities and for dissipatingheat from said -cooling liquid inlaheat exchanger located remotely from said cylinder, another of said cavities being formedto provide an exposed heat exchanging wall adjacent cylinder and to provide thermo-syphon circulation of cooling liquid between said cylinder and said wall.

13. An engine cooling system comprising a plurality of cylinders having cooling liquid circulating cavities formed on opposite sides of said cylinders, a wall formed adjacent. said cylinders and on one side `of said cylinders for-.dissipating heat absorbed by cooling liquid circulating by thermo-syphon circulation of said cooling liquid in one of said cavities and adjacent said Wall, yand means for circulating cooling liquid through a cavity on the other side of said cylinders and for dissipating the heat from said cooling liquid in a-region remote from said cylinders 14. Anengine cooling system comprising a plurality of cylinders having cooling liquid circulating vcavities formedl on opposite sides: of said cylinders, `a=wall formedv adjacent said cylinders and on .one side of said cylinders for dissipating the heat absorbed by cooling'liquid circulating by thermo-syphon circulationof said cooling liquid in one of said cavities and adjacent said wall, and

means Vfor circulating cooling liquid through a cavity on the other side of said cylinders and for dissipating the heat from said cooling liquid in a heat exchange device located away vfrom said cylinders and said block.

.l 15. An engine cooling system comprising Aa water pump having an outlet, an engineblock having a lubricant cooler. secured thereto and a jacket surrounding said cooler and connected to said outlet, said engine block having a plurality of exhaust passages' extending throughout the length l of one side thereof for exhausting the cylinders of said engine, a cooling water distribution manifold formed in said block below .said passages and extending from one end to the other of said block', a water supply conduit connected at one end with said lubricant cooler jacket vbeyond said lubricant cooler in said jacket and at the other end to the middle portion of said distribution manifold, a plurality of exhaust cooling passages forrned in said block and communicating with said distributionmanifold throughout, the length of said distribution manifold and extending normally from said distribution manifold and upwardly in `said block between said'exhaust pas- 1121 sages in said block, a plurality of cylinder cooling cavities formed in said block and communieating with the upper extremities of said exhaust cooling passages, said cavities being formed in said block around the head ends of said cylinders and being adapted to extend downwardly of said cylinders on the side of said block opposite said exhaust passages, and outlet means formed in the upper part of said block for exhausting said cooling water from the upper parts of said cylinder cooling cavities.

16. An engine cooling system comprising a cooling fluid circulating pump having an outlet, a lubricant cooling device having a jacket connected to said outlet and having a jacket outlet beyond said lubricant cooling device, an engine block having a plurality of aligned cylinders formed therein, said block being formed to provide a plurality of parallel and laterally disposed exhaust passages leading from said cylinders and communicating with the exterior of said block and vextending throughout the length of said block, a cooling liquid distribution manifold communicating with said jacket outlet and formed in said block below said exhaust passages and being provided with branch passages extending throughout the length thereof and formed in said block between said exhaust passages, cylinder cooling cavity means formed on the vside Vof, said block opposite said exhaust passages and extending-downwardly from adjacent the head end of said cylinders to portions of said cylindersbelow the level of said exhaust passages formed inY said block, said cylinder cooling cavities being formed to provide extensions thereof projecting across the top of said block and between said cylinders and communicating with said branches above said exhaust cooling passages, and a plurality of outlets formed in said block and communicating with said extensions of said cylinder cooling cavities for exhausting said cooling liquid from said block. l

e 17. An engine cooling system comprising an engine block having a plurality of spaced and aligned cylinders formed therein, said block being formed to provide va plurality of cylinder cooling cavities therein, said cavities being disposed on one side of said cylinders and extending throughout the length of said block, said cavities being formed in said block to provide aplurality of laterally disposed extensions projecting `acrossthe upper part of said block and between said cylin` ders, a plurality of exhaust passages formed in said block in parallel relation to one another and leading from said cylinders to the exterior of said block, said exhaust passages being formed in said block in sp-aced'relation to one another to provide a plurality of exhaust cooling passages disposed in parallel relation to one another throughoutthe length of said block, said exhaust cooling passages and said cavity extensions being adapted to communicate with one another through a cooling fluid receiving passage formed in said` block above said exhaust passages, and a distributionmani- .fold formed in said block y and extending throughout the length of said block and below said exhaust passages for circulating and distributing liquid through said exhaust cooling pas-` sages, said extension cavities and said cylindery cooling cavities.

18. An engine cooling system comprising a block having a plurality of aligned cylinders formed therein, a cam shaft mountedin said block and extending throughout the length thereof alongthe lower extremities ofsaid cylinders, a plurality of engine cooling cavities -sa'gesxbeing adapted to .communicate with the re- -mainder of= said cylinder cooling cavities.

36. AniV engine` bl'ockncomprising ,an integrated metallic body vhaving side walls, .front :and rear `end Zwalls, a top Wall, VandzaA plurality of :aligned cylinders-formed therein 'in'spaced relation tosaid sideand-end walls and to one another, an vinlet 'manifld formed Ain said block` and having braluiches'l thereof extending betweensaid cylinders and at the ends ofsaidrcylinders;aplurality ofexhaust passages formed in said block and above'said manifold' 'and leading froml said :cylinders to the-exterior of said lblock,"saidiblock being-frmedbetween said .inlet manifoldland s'aid exhaust passages to providea cooling 'liquid distribution manifold formed in said block from one end to the otherfof said block, saidfexhaust'passages beingspaced. from one another an'dformed vin said Vblock -to provide exhaust cooling. passages communicating at the lower extremities thereof with'said vcooling liquid distribution manifold, said block also being formed lto provide acooling 'liquidreceivingpassage below the upper wall of said blockand communicating with said exhaust cooling passages,- said upper wall ofsaidlblock being-formed toprovide outlets from said 1liquid receiving passage. Y

37.l An engine block comprising an integrated metallic body having side walls, front and-rear -endwalls,-a top wall, anda plurality'of aligned cylinders formed therein ink spaced'relation to saidside and endwalls and to one another, an inlt 4manifold' formed lin `said-block Yand'having branches'thereof `extending between said cylinders and at the endsof -sai'dcylinders, a plurality `of l"exhaust passages f formed in said block and above said manifold .and leading from saidy rcylinders to the exterior-of said block, said blockbeing formed `between'said inlet manifold and said'exhaustpassages-'ItoV provide acooling liquid distribution manifold Sformed in said block from one endl-tothe `other of said block, saidexhaust passages beingv spaced from one another and formed inA said block to provideexhaust*cooling-passages 4communicating atlthe lower extremities thereof with said cooling 'liquid distribution manifold, said block being formed to provide a cooling fliq'- uid-"receiving passage below 'the upper Wall of said block and communicating with said exhaust cooling passages, said-V upper wall of Vsaid block 'beingl formed Ato provideoutlets from said liquid Ereceiving passage, saidblock also being formedto provideva supply passage for said liquid distribution, manifold, saidv supply passage being Aadapted to intersectsaid liquid receiving passage and .be-

'ing disposed between and in parallel relation to certainof said exhaust cooling-passages;

'38; An engine block' comprisinganintegrated metallic body having side walls, frontand rear end -walls,vatop Wall, and a plurality of aligned cylinders formed therein in spaced relation to -saidfsidevand end walls and "to one another, said block'` also being .formed to provide coolingliquid circulating-cavities on opposite sides fof said cylinders and extending downwardly -of'said cylinders towards'.v the crank. ends -Lofsaidcylinders said blockfurther beingformed to separate said cavi- "ties Yatithe loweriextremities of 'said cavities and to providezcommunication between saidcavities only tbetween andaround the upper extremities of `said cylinders, said Y, walls vof said block being formed -to provide acoolingliquid inlet to Voneof said cavities ,and Van -outlet from -each -of said cavities., y B9.Y An engine block comprisingan integrated 20 metallicbody having vside walls, front and? rear end walls, a top wall, anda pluralityof aligned cylinders vformed therein in' spaced .relationto saidtside and end wallsand to .one another; said block also-being formed to provide. cooling rliquid circulating cavitieson opposite'sides of said cylinders and extending downwardly'of saidtcylinders towards the crank ends .of said cylinders';sai'd blockA further 'being formed to separatesaidi cavities at :thelower .extremities'of said cavities'cand to provide communi-cation between said cavities between and around the-upper extremitiesof said cylinders, ,saidA wallsof said rblock beingform'ed to 'provide'a coolingpliquid inlet to the lower rextremitieslof certain of said Ycavities on 'one'sidefof `said `blockand an :outlet'from said cavities from said communication between said cavities.

40'. An iengine block comprising an integrated lmetallic body havingv side walls, frontV andrlrear 'end walls, aztop wall, and a' .pluralityof 'aligned culating :cavities von opposite sides of said cylindersand extending downwardly of said cylinders towards the crank'ends of said cylindersgsaid Walls'of said block being formed to provide-'a cooling liquid inlet to the lower Iextremity'of one of said cavities and an outlet from the upper ex'- tremity of said cavity.

41. An engine iblock comprising an integrated metallic body having sidewalls, front and rear end'walls,v a top wall, and a .plurality of aligned cylinders lformed .therein in spaced relation" to said'side -and .end vwalls .and vto one another,` 'an inlet manifold formed in said block' and having branches thereof extending between said-cylinders and at the-ends offsaid cylinders, a'p'lurali'ty of. exhaust passages formedfin said blockv and above said manifold` and leading from said cylinders :to the exterior of said block,'saidlblock -being formed between said inletm'anifold andl said exhaust passages Yto provide a cooling liquid distribution manifold formed in said block from one end to the other of saidbloclr, said exhaustpassages being spaced from one 'another and form'ed in said 'block to provide exhaust cooling passages communicating at the lower rextremities thereof with said cooling liquid distribution mani-fold, said vblock being formed to provide a cooling liquid receiving'passage below the upper wall of said .block land communicating with said exhaust cooling passages, said upper Wall of'said block being formed to provide outlets from said liquid receiving passage, said'block being formed to pro- 'vide an inlet Afor said liquid distribution manifold,

and saidblock being further formed to provide thermo-syphon circulation cooling cavity'means on vthe side of said cylinder opposite said manifold.`

42.' An engine block comprising an' integrated metallic body having side walls, front rand -rea-r Vend'vvalls, a topwall, and a plurality 'of aligned cylinders formed therein in spaced relation' to lsaidl side'and end walls and to one anotherg-an 21 passages being spaced from one another and formed in said block to provide exhaust cooling passages communicating at the lower extremities thereof with said cooling liquid distribution manifold, said block being formed to provide a cooling liquid receiving passage below the upper wall of said block and communicating with said exhaust cooling passages, said upper wall of said block being formed to provide outlets from said liquid receiving passage, said block also being formed to provide an inlet for said liquid distribution manifold, said inlet being adapted to supply cooling liquid to said manifold for circulation upwardly through said exhaust cooling passages and outwardly through said outlets, and

cooling cavity means formed in said block on the side of said cylinders opposite said receiving passage and communicating with said receiving passage through supply passages formed around theupper extremities of said cylinders.

43. An engine block comprising an integrated metallic body having side walls, front and rear end walls, a top wall, and a plurality of aligned cylinders formed therein in spaced relation to said side and end walls and to one another, an inlet manifold formed in said block and having branches thereof extending between said cylinders and at the ends of said cylinders, a plurality of exhaust passages formed in said block and above said manifold and leading from said cylinders to the exterior of said block, said block being formed between said inlet manifold and said exhaust passages to provide a cooling liquid distribution manifold formed in said block from one end to the other of said block, said exhaust passages being spaced from one another and formed in said block to provide exhaust cooling passages communicating at the lower extremities thereof with said cooling liquid distribution manifold, said block being formed to provide a cooling liquid receiving passage below the upper wall of said block and communicating with said exhaust cooling passages, cooling cavity means formed in said block on the side of said cylinders opposite said receiving passage and communieating with said receiving passage at the upper extremities of said cooling cavity means, said block being provided with connections for the forced circulation of cooling liquid into said distribution manifold and outwardly through openings formed in said upper wall of said block and communicating with said liquid receiving passage.

114. An engine block comprising an integrated metallic body having side walls, front and rear end walls, a top wall, and a plurality of aligned cylinders formed therein in spaced relation to said side and end walls and to one another, an inlet manifold formed in said block and having branches thereof extending between said cylinders and at the ends of said cylinders, a plu-` rality of exhaust passages formed in said block and above said manifold and leading from said cylinders to the exterior of said block, said block being formed between said inlet manifold and said exhaust passages to provide a cooling liquid distribution manifold formed in said block from one end to the other of. said block, said exhaust passages being spaced from one another and formed in said block to provide exhaust cooling passages communicating at the lower extremities thereof with said cooling liquid distribution manifold, said block being formed to provide a cooling liquid receiving passage below the upper wall of said block and communicating with said exhaust cooling passages, said block being formed to provide inlet connections for supplying cooling liquid to said liquid distribution manifold and outlet connections for exhausting said cooling liquid from said liquid receiving passage.

I-IARGLD H. ALBINSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,330,436 Fekete Feb. 1Q, 1920 1,793,713 Morrill Feb. 24:, 1931 2,175,448 Schlagintweit Oct. l0, 1939 2,334,731 `Szekely Nov. 2-3, 1943 FOREIGN PATENTS Number l Country Date 332,523 Great Britain of 1930 

